GoToSocial/vendor/github.com/go-playground/form/v4/cache.go

134 lines
2.5 KiB
Go
Raw Normal View History

package form
import (
"reflect"
"sort"
"strings"
"sync"
"sync/atomic"
)
type cacheFields []cachedField
func (s cacheFields) Len() int {
return len(s)
}
func (s cacheFields) Less(i, j int) bool {
return !s[i].isAnonymous
}
func (s cacheFields) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
type cachedField struct {
idx int
name string
isAnonymous bool
isOmitEmpty bool
}
type cachedStruct struct {
fields cacheFields
}
type structCacheMap struct {
m atomic.Value // map[reflect.Type]*cachedStruct
lock sync.Mutex
tagFn TagNameFunc
}
// TagNameFunc allows for adding of a custom tag name parser
type TagNameFunc func(field reflect.StructField) string
func newStructCacheMap() *structCacheMap {
sc := new(structCacheMap)
sc.m.Store(make(map[reflect.Type]*cachedStruct))
return sc
}
func (s *structCacheMap) Get(key reflect.Type) (value *cachedStruct, ok bool) {
value, ok = s.m.Load().(map[reflect.Type]*cachedStruct)[key]
return
}
func (s *structCacheMap) Set(key reflect.Type, value *cachedStruct) {
m := s.m.Load().(map[reflect.Type]*cachedStruct)
nm := make(map[reflect.Type]*cachedStruct, len(m)+1)
for k, v := range m {
nm[k] = v
}
nm[key] = value
s.m.Store(nm)
}
func (s *structCacheMap) parseStruct(mode Mode, current reflect.Value, key reflect.Type, tagName string) *cachedStruct {
s.lock.Lock()
// could have been multiple trying to access, but once first is done this ensures struct
// isn't parsed again.
cs, ok := s.Get(key)
if ok {
s.lock.Unlock()
return cs
}
typ := current.Type()
cs = &cachedStruct{fields: make([]cachedField, 0, 4)} // init 4, betting most structs decoding into have at aleast 4 fields.
numFields := current.NumField()
var fld reflect.StructField
var name string
var idx int
var isOmitEmpty bool
for i := 0; i < numFields; i++ {
isOmitEmpty = false
fld = typ.Field(i)
if fld.PkgPath != blank && !fld.Anonymous {
continue
}
if s.tagFn != nil {
name = s.tagFn(fld)
} else {
name = fld.Tag.Get(tagName)
}
if name == ignore {
continue
}
if mode == ModeExplicit && len(name) == 0 {
continue
}
// check for omitempty
if idx = strings.LastIndexByte(name, ','); idx != -1 {
isOmitEmpty = name[idx+1:] == "omitempty"
name = name[:idx]
}
if len(name) == 0 {
name = fld.Name
}
cs.fields = append(cs.fields, cachedField{idx: i, name: name, isAnonymous: fld.Anonymous, isOmitEmpty: isOmitEmpty})
}
sort.Sort(cs.fields)
s.Set(typ, cs)
s.lock.Unlock()
return cs
}